Press the bolt FORWARDS...(Twards the feedneck) And it will get rid of any extra pressure. Even if there is 100 psi left (((((When it is un-cocked)))))

Have one person hold the gun and you hold the tank (or the other way around) and both of you push the oppisite way (The way the tank comes off=)))) And do that as hard as you can. It should loosen up a little